Đáp án:
Giải thích các bước giải:
a,⇔2x+7=-135
⇔ 2x. =-142⇒ x=-71
b,⇔$\frac{1}{2}$x= $\frac{3}{5}$ ⇒ x=$\frac{6}{5}$
c,⇔$\frac{1}{2}$x+$\frac{3}{2}$ x=2020
⇔2x=2020 ⇒x=1010
d,⇔10- I x+1I=5
⇔ I x+1I=5
Th1 : x+1<0 ⇒I x+1I=-x-1
⇔-x-1=5⇒ x=-6
Th2: x+1≥0 ⇒I x+1I= x+1
⇔x+1=5⇒ x=4
e, -,06x-$\frac{7}{3}$ =$\frac{27}{5}$
⇔ -0,6x =$\frac{81}{15}$+$\frac{35}{15}$
⇔-0,6x =$\frac{116}{15}$
⇔ x. =$\frac{116}{15}$.(-$\frac{5}{3}$)=-$\frac{116}{9}$
g,⇔ 2,8:$\frac{7}{5}$=$\frac{1}{5}$-3x
⇔$\frac{14}{5}$.$\frac{5}{7}$=$\frac{1}{5}$-3x
⇔2=$\frac{1}{5}$-3x
⇔2-$\frac{1}{5}$=-3x
⇔$\frac{9}{5}$=-3x ⇒ x=$\frac{-3}{5}$
